1. Field of the Invention
The present invention relates to a photosensitive material processing apparatus for feeding a photosensitive material into a processing tank such as a developing tank to develop the photosensitive material.
2. Description of Related Art
In a photosensitive material processing apparatus, a photosensitive material such as photographic film or photographic printing paper, on which an image has been exposed, is fed into a developing apparatus. In the developing apparatus, the photosensitive material is successively passed through a series of processing tanks such as a developing tank and a fixing tank. In detail, the photosensitive material is fed into a processing tank while being nipped by inlet guide rollers provided at the inlet of the processing tank. After being passed through a processing solution in the processing tank, the photosensitive material is pulled out of the processing tank and is transported to the next stage while being nipped and driven by outlet guide rollers provided at the outlet of the processing tank.
When the photosensitive material enters a developing tank, a developing solution contacts the photosensitive material, thereby starting development. If the developing solution contacts a portion of the photosensitive material before that portion enters the developing solution, development of that portion progresses faster than the remaining portion. This causes developer streaks or unevenness in development. The contact of a developing solution to a photosensitive material at an early stage of processing occurs when the developing solution which has carelessly soiled the inlet guide rollers contacts the photosensitive material. The developing solution on the inlet guide rollers sometimes produces, due to oxidation thereof, a substance which suppresses the developing reaction. In such a case, development is delayed with a portion soiled by the developing solution. This also causes developer streaks or unevenness in development.
The reason why a developing solution can be unintentionally adhered to the inlet guide rollers is that when the developing solution smudges a certain stationary guide roller which is located above the solution and the photosensitive material hits the stationary guide roller, the developing solution splashes, and the splashed developing solution sometimes adheres to the inlet guide rollers. Further, when the inlet guide rollers and the outlet guide rollers are both taken out for cleaning, the developing solution carried on the outlet guide rollers as the photosensitive material is transported drips onto the inlet guide rollers after the outlet guide rollers are taken out. Moreover, there is a possibility that developing solution evaporated due to heat contacts the inlet guide rollers and condenses into drips as the temperature decreases, so that the developing solution adheres to the inlet guide rollers.